diff options
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/psci.c | 139 |
1 files changed, 124 insertions, 15 deletions
diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index 355b9e38a42d..87927f7e1ee7 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -438,42 +438,103 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu) { - return 1; /* PSCI version */ + return 3; /* PSCI version and two workaround registers */ } int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) { - if (put_user(KVM_REG_ARM_PSCI_VERSION, uindices)) + if (put_user(KVM_REG_ARM_PSCI_VERSION, uindices++)) + return -EFAULT; + + if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1, uindices++)) + return -EFAULT; + + if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2, uindices++)) return -EFAULT; return 0; } +#define KVM_REG_FEATURE_LEVEL_WIDTH 4 +#define KVM_REG_FEATURE_LEVEL_MASK (BIT(KVM_REG_FEATURE_LEVEL_WIDTH) - 1) + +/* + * Convert the workaround level into an easy-to-compare number, where higher + * values mean better protection. + */ +static int get_kernel_wa_level(u64 regid) +{ + switch (regid) { + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: + switch (kvm_arm_harden_branch_predictor()) { + case KVM_BP_HARDEN_UNKNOWN: + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL; + case KVM_BP_HARDEN_WA_NEEDED: + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL; + case KVM_BP_HARDEN_NOT_REQUIRED: + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED; + } + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL; + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2: + switch (kvm_arm_have_ssbd()) { + case KVM_SSBD_FORCE_DISABLE: + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL; + case KVM_SSBD_KERNEL: + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL; + case KVM_SSBD_FORCE_ENABLE: + case KVM_SSBD_MITIGATED: + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED; + case KVM_SSBD_UNKNOWN: + default: + return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN; + } + } + + return -EINVAL; +} + int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { - if (reg->id == KVM_REG_ARM_PSCI_VERSION) { - void __user *uaddr = (void __user *)(long)reg->addr; - u64 val; + void __user *uaddr = (void __user *)(long)reg->addr; + u64 val; + switch (reg->id) { + case KVM_REG_ARM_PSCI_VERSION: val = kvm_psci_version(vcpu, vcpu->kvm); - if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id))) - return -EFAULT; + break; + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: + val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK; + break; + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2: + val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK; - return 0; + if (val == KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL && + kvm_arm_get_vcpu_workaround_2_flag(vcpu)) + val |= KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED; + break; + default: + return -ENOENT; } - return -EINVAL; + if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id))) + return -EFAULT; + + return 0; } int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { - if (reg->id == KVM_REG_ARM_PSCI_VERSION) { - void __user *uaddr = (void __user *)(long)reg->addr; - bool wants_02; - u64 val; + void __user *uaddr = (void __user *)(long)reg->addr; + u64 val; + int wa_level; + + if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id))) + return -EFAULT; - if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id))) - return -EFAULT; + switch (reg->id) { + case KVM_REG_ARM_PSCI_VERSION: + { + bool wants_02; wants_02 = test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features); @@ -490,6 +551,54 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) vcpu->kvm->arch.psci_version = val; return 0; } + break; + } + + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: + if (val & ~KVM_REG_FEATURE_LEVEL_MASK) + return -EINVAL; + + if (get_kernel_wa_level(reg->id) < val) + return -EINVAL; + + return 0; + + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2: + if (val & ~(KVM_REG_FEATURE_LEVEL_MASK | + KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED)) + return -EINVAL; + + wa_level = val & KVM_REG_FEATURE_LEVEL_MASK; + + if (get_kernel_wa_level(reg->id) < wa_level) + return -EINVAL; + + /* The enabled bit must not be set unless the level is AVAIL. */ + if (wa_level != KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL && + wa_level != val) + return -EINVAL; + + /* Are we finished or do we need to check the enable bit ? */ + if (kvm_arm_have_ssbd() != KVM_SSBD_KERNEL) + return 0; + + /* + * If this kernel supports the workaround to be switched on + * or off, make sure it matches the requested setting. + */ + switch (wa_level) { + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL: + kvm_arm_set_vcpu_workaround_2_flag(vcpu, + val & KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED); + break; + case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED: + kvm_arm_set_vcpu_workaround_2_flag(vcpu, true); + break; + } + + return 0; + default: + return -ENOENT; } return -EINVAL; |